The present invention relates to video processing (e.g., video decoding), and more particularly, to a video processing apparatus for storing partial reconstructed pixel data in a storage device for use in intra prediction and a related video processing method.
The conventional video coding standards generally adopt a block based coding technique to exploit spatial and temporal redundancy. For example, the basic approach is to divide the whole source picture into a plurality of blocks, perform intra/inter prediction on each block, transform residues of each block, and perform quantization and entropy encoding. Besides, a reconstructed picture is generated in a coding loop to provide reference pixel data used for coding following blocks. For certain video coding standards, in-loop filter(s) maybe used for enhancing the image quality of the reconstructed frame.
The video decoder is used to perform an inverse operation of a video encoding operation performed by a video encoder. For example, the video decoder also has an intra prediction unit used to generate predicted pixels needed for generating a reconstructed frame serving as a reference frame. For certain video coding standards, the intra prediction of a current block being decoded requires reconstructed pixels of previously decoded block (s). However, using a picture buffer with a capacity not smaller than a reconstructed data size of one picture for buffering each reconstructed pixel generated from a reconstruct unit is not cost-efficient. Hence, there is a need for an innovative low-cost video decoder design which can use a small-sized buffer for buffering reconstructed pixels needed by intra prediction of one block to be decoded.